Tractor transmission



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272722Z F /VanO/z'z A TTORNEYS' 'Patented 001;. 25, 1921.

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E. F. NORELIUS. TRACTOR TRANSNHSSiON. APPLICATION FILED SEPI. I 7.

Patented Oef. 25,

3 SHEETS-SHEET 2.

EF. NORELIUS.

TRACTOR TRANSMISSION.

APPLICATION FILED SEPT. 17, 191s.

1,395,004, Patented oct. 25, 1921.

3 SHEETS-SHEET 3. x! H 1 i fl A TTORNE YS UNITED STATES PATENT OFFICE.

EMIL F. NORELIUS, OF PEORIA, ILLINOIS, ASSIGNOR T THE HLT MANUFACTURING COMPANY, OF STOCKTON, CALIFORNIA, A CORPORATION 0F CALIFORNIA.

` TRACTOR TRANSMISSION'.

Specification of Letters Patent.

Patented oct. 25, 1921'.

Application led Sentember 17, 1918. Serial No. 254,443.

' type, it has been found that one of the prime of a tractor, without anv appreciable powerI factors in the proper performance of the vehicle is to provide positive means for contrlling and varying the relative lineal speed of travel of the vtracks to e'ect a steering of the vehicle. to provide a transmission with variable speed driving means adapted to separately operate the two tracks of the vehicle, and which means are controlled by friction clutches. These members cause a considerable loss of power due to friction and furthermore often become inoperative or develop a slipping action between their members at which time the steering will not be positive. It is, therefore, the prime .object of the present invention to provide positive means for continu-K ously and variably driving separate tnacks loss and insuring that all of the driving elements will b e in positive engagement at all times, thus eliminating an interposition of friction clutches, and other separable driving members in the delivery of power.

The present invention embodies the use of a variable speed transmission of common construction 1n connection with which dual differential mechanisms are provided, said mechanisms being capable of uniform rotation or variable relative speeds, the control of said differentials being indirectly eifected by the rotation of the main transmission drive shaft as initiated by the manlpulatlon of .independent clutch members.

The invention is lillustrated by way of ex lample in the accompanying drawings in whiche Figure l is aview in side elevation illustrating the transmission as applied for use It has been common practice upon a. tractor of the lcommon chain' tread track type.

Flg. 2 1s a view 1n vertical transverse section and elevation illustrating the transmission, and particularly disclosing the means concerned with the steering thereof.

Fig. Sis a view in longitudinalvertical section through the transmission illustrating the steering means, as well as the speed changing structure.

Fig. iis avertical transverse section on line 4 4 of Fig. 2.5

' Referring more particularly to the drawings, 1() indicates a gear case of suitable design,` which is Yprovided with bearings for receiving a main drive shaft l1, and a jack shaft 12;` VThis last named shaft is disposed in parallel spaced relation to the drive shaft and therebeneath. .The drive shaft extends the full iength of thecase, and s provided jat its driving end with speed changing gears 13, 14: and 15, which are adapted to be brought-into driving relationto complemen tary gears 16, 16a, 17, 18 and 19. The oonstruction and manipulation of these gears does not require explanation, as they conl stitute a common three-speed transmission with which the present invention is notparticularly concerned, except as they determine the various turning arcs described by the vehicle as it ltravels at different speeds.

The stub shaft 12 is providedat its inner endwith a bevel gear pinion 2l in mesh with bevel gear 22. This gear is iixed'upon a transverse driving shaft 23 by which power is indirectly transmitted to opposite truck bull gears 24 and 25 of the tractor. A gear 22 is disposed substantially'at the middle of theV length of the shaft 23 and between individual planetary gear sets 26 and 27 which separately affect the gears 24: and 25', respectively.

The planetary gear transmissions each l and extends outwardly through a' bearing in the side of the case. Here it is itted'with a driving pinion 33. This pinion may be designed to mesh with the bull gear at each side ofthe mechanism, or may be inclosed by the driving sprocket of the truck if the construction will so permit. In any event the member 32 is provided to drive'one of the side tracks of the tractor. It will be understood that this planetary gearlstructure Vis made in duplicate, and that by this dual application the two tracks of the tractor will be separately actuated as the transverse shaft 23 is driven through rotation on the-.jack

shaft ,12.

In order to establish a cooperating movement between the planetary gear sets, they are provided with large bevel gears 34,

i which are placed on the adjacent inner faces of the spiders 28, and mesh with an interposed bevel pinion 35. This pinion is keyed to a vertically extending shaft 36, which is rotatably secured in a bearing formed through tlie top plate 37 of the transmission case. It will be readily recognized that a stationary condition of the connecting pinion 35 will cause operation of the` planetary gear sets to drive the opposite trucks of the v A tractor forwardly as impelled by the transmission. Rotation ofthis gea-r, however, will rotate the spiders of the two transmissions in diametrically oppositedirections,

'and will cause one of the chain tracks to move at a speed greater than the speed of the i mission, that is, upon opposite sides of the axis of shaft 36 as the latter is in the same Avertical plane with-the axis of the transverse shaft 23. The cone members 38 and 39 are formed at their adjacent ends with bevel pinions 40 and 41, which are constantly in mesh with a common bevel gear 42 keyed upon the shaft 36, and disposed directly above the connecting bevel gear 35 previously described. The two cone clutches may be separately and selectively driven from the shaft 11 byy slidable clutch'members 43 and 44, which are splinedupon the shaft 11, and

.are controlled by suitable shifting yokes,

' with which a steering lever is connected.

Inequalities in the roadway will oier variable resistance to two tracks of the vehicle and'will cause them to operate at different speeds as: permitted by the differential gearing in the transmission. To avoid this'v a brake.drum 45 isxed to the gear 42 and is normally gripped by a band 46 ,actuated in relation to each other. As the jack shaftv 2 is rotated it` imparts motion to the transverse shaft 23 through the pinion 21 and the gear 22. This motion produces simultaneous rotation of the complementary A ears 31 in each of the planetary gear sets.- s these gears rotate they are engaged by the pinions 29,'which are also in mesh with the ring gears 30, and will, under ordinary conditions cause the twov sleeve drums 32 to rotate at equal speeds and in unison with the drive shaft ,23. This construction, however,

`provides for differential movement, which is common in vehicle power transmission mechanisms, andnormally eliminated by the brake band 46. In case a positive variable speed ratio is to .be established between the two tracks of the vehicle, one of the clutches 43 or 44 isthrown into mesh with its re- 1 spective, clutch cone by means of t'hesteerin' mechanism` as the brake is released. This will lock the cone to rotate with the main drive shaft, and indirectly act through gear 42 to produce the desired and continued rotation of the connecting pinion 35. This speed of rotation will directly influence the effective speeds of rotations of the drum sleeves through theirspiders, and cause one of the drums to -increase its speed, while decreasing the speed of the opposite drum.

It will' be ,noted that the minimum and maximum speeds of the opposite tracks will be in equal ratio and relation to the mean speed of the vehicle as in the case when'the two tracks were moving at equal speeds.

Attention is further directed to the fact that all-of the gears concerned in the variable speed drive are in constant mesh, and the clutch action is transferred from the'original set ofdriving clutches to a set of minor clutches, which merely operate the speed varying means. Manipulation 0f the speed changegears will cause the vehicle to describe different arcs as determined by thedriving ratio of the `shaft 23 in relation to the speedpof the gear spider.

It will thus be seen'that the structure h ere disclosed affords a continuous and positive driving means for the tracks of a chain tread tractor, and, at the same ltime allows the lineal speed of said tracks to be ositively varied without the possibility o inoperation in the transmission means.

the radius is short and the curve described by the tractor is sharp.

Having thus describedv my invention, what I claim and desire to secure by Letters Patent is:

1. Thecombination of a pair of driven members, a drive member, planetary gearing between the drive member and each driven member, rotatable means interposed between opposite planetary gear sets and connected to a speed changing element in each of the latter for controlling the same, and power operated means for actuating said last mentioned control means in either direction whereby to produce a differential rotation of said planetary gear sets.

, 2.The combination of a pair of driven members, a drive member', planetary gear ing. between the drive member and each driven member, rotatable means interposed between opposite planetary gear sets and connected to a speed changing element in each ofthe llatter for controlling the same, power operated means for actuating said last mentioned control means, and operative connections between the power' operated means and the control means for actuating the latter in either direction and at variable speeds. Y

3. In a tractor transmission, a main shaft, a driving axle disposed at right angles to said shaft, speed changing gears adapted to impart motion from the'main shaft to the axle, separate planetary gear sets actuated by the rotation vof said axle and power driven means for positivelylactuating said gear sets to produce. an acceleration in the speed of one set, and a proportionate retardation in the speed of the other set while being drlven by the constantly rotating action.

4. In a tractor transmission, a main shaft, a driving axle disposed at rightangles to said shaft, speed changing gears adapted to imlpart motion from the main shaft to the ax e by the rotation of said axle and power driven means for positively actuating'said gear sets to producean acceleration 1n the speed of one set, a proportionate retardation in the speed of the other set while being driven by the constantly rotating action, and means whereby predetermined speed ratios may beestablished between the two lgear sets and the driving axle'.

5. Ina'tractortransmission, a main shaft,

a transversely extending driving axle, gears unitingtheax e..and the shaft, driving gears -lixed to the axle, gear spiders rotatably dis'- separate planetary gear sets actuated posed around the axle, planetary gears carried by the spiders and in mesh with the driving gears, gear sleeves circumscribing the planetary gears and driven thereby, and means whereby the gear spiders may be positively rotated in opposite directions to each other while the gears carried thereby are driven in a single direction, thuscausing variation in the driving speeds of the two gear sleeves.

6. In a tractor transmission, a main shaft, a transversely extending driving axle, gears uniting the axle and the shaft, driving gears fixed to the axle, gear spiders rotatably disposed around the axle, planet-ary gears carried by the spiders and in mesh with the driving gears, gear sleeves circumscribing the planetary gears and driven thereby, means whereby the gear spiders may be positively rotated in-opposite directions to each other while the gears carried thereby are driven in a single direction, thus causing variation in the driving speeds of the two gear sleeves, and means normally holding said gear spiders in fixed relation to each other.

7. A power transmission mechanism comprising a constantly rotating main shaft, a jack shaft, speed changing'gears. adapted to be selectively operated to connect the two shafts, a transversely extending driving axle continuously rotated by the jack shaft, sep? arate driving units carried at the opposite ends of said axle, and means affected by the rotation of the main shaft whereby the speed-of rotation of, the driving' units may be positively varied inversely.

8. A power transmission mechanism comprising a constantly rotating main shaft, a jack shaft, speed changing gears adapted to be selectively operated to connect the two shafts, a. transversely extending driving axle continuously rotated by the jack shaft, separate driving units carried at the opposite ends of said axle, selectively operated steering clutches upon the 'main' shaft, and means whereby Jalternate engagement of said clutches 'will positively affect the driving ,units to produce an alternate acceleration 1n the driving speed of Said units.

S A power transmission mechanism comprising-a constantly rotating main shafta jack shaft, speed'changing gears adapted to .ends of said axle, selectively operated steering clutches upon the main shaft, means whereby alternate engagement of said clutches will positively affect the; driving units to produce an alternate acceleration in the driving speed ofl said units, and means for normally` holding said speed changing mechanism against operation.

l l0. In a tractor transmission, a constantly rotating main shaft, a pair of separate gears carried by said shaft, a steering gear with which both of said gears are in mesh, clutch mechanisms for connecting the gears in driving relation to the main shaft, a single control mechanism for alternately actuating said clutches, a driving axle driven bythe -main shaft, separate driving units at the oppos-ite ends of said axle, and means connectingthe dr1v1ng units with the steering'gear wherebypositive speed variation may be produced between the driving units. 11. In a tractor transmission, 'a constantly rotating main shaft, a pair of separate gears:

v gear mechanism against operation.

, l2. In a tractor transmission, amain shaft, a driving shaft at right angles thereto, and adapted 'to be rotated thereby, separate driving units carried upon the axle, said units comprising independent driving sleeves, driving g'earsix'ed tothe axle and interposed planetary gears, rotatable spiders car- -rylng said gears, operating gears fixed to,

each of said spiders, a common steeringgear meshed with both of said operating gears, a4 secondary steering gear carried by the shaft of .the main steering gear,.separately'oper ated gears mounted upon the main shaft, and-y l in mesh with said secondary gear, and clutch` means for each Aof said main shaft gears l whereby theymay be alternately connected with the main shaft to e'ect rotation-of the steering gears and' oppositely rotate the.

spider gears.

v13. The combination of a pair of driven members, a drive member, planetarygeari'ng between the drive member and each of the driven members, rotatable means interposed .between opposite planetaryl gear sets and connected to a speed changing element inl each of the latter for controlling the same, a

power driven member and oppositely rotatingxcontrollable connections between the ipower driven member and the control means. :L .14. The combination of a palr of driven members, a drive member,planetary gearing between the drive member and each of the .driven members, rotatable means interposed between oppositel planetary gearsets and connected vto aspeed changing element in each of `the latter for controlling'the same,-

a power driven memberl and oppositely rotating connections between the power shaft and the control Ineansand a controllable friction 'clutch included in each of t-he said connections. 1

. l5. The combination of a pair of driven members, a drive member, a planetary gear set between the drive member and each driven member, including a normally inactive spider on which the intermediate gears of the planetary set are journaled, a ring -gear for each -of said spiders, and a controllable power operatinggea intermeshing with said ring gears whereby to affect said planetary gear sets in a manner to produce a positive differential driving action.

In testimony whereof I have hereunto set my hand in the presenceof two subscribing witnesses.

EMIL F. NoRELrUs.

Witnesses:

C. A. WHITNALL, F. ZOBRISKIE. 

